Dr Carol Turley, a senior scientist at the UK Ocean Acidification Research Programme at Plymouth Marine Laboratory, said studies already show shell fish are struggling to grow.

She feared tiny molluscs, known as ptetropods or ‘sea butterflies’, that are important to the wider ecosystem, may reduce in number affecting a number of larger fish.

“One could see a reduction in salmon,” she said. “Ocean acidification may have significant future impacts on catches of crabs, mussels and other shellfish; species dependent on coral reefs and ones such as salmon that feed on smaller, shell building organisms lower down the food chain know as ptetropods.”

The report ‘Environmental Consequences of Ocean Acidification: A Threat to Food Security’ was released during the latest round of UN climate change talks in Cancun.

Dr Turley said billions of people rely on fish like salmon to survive.

She called on the world to agree a cut in emissions so that ocean acidification does not impact on fish like salmon and ultimately global food security.

“It is likely that if CO2 emissions continue at the same rate ocean acidification will have a considerable influence on marine-based diets for billions of people worldwide,” she added.